דברים, פרק ט״ו, פסוק כ״א

Bringing an offering to God requires physical perfection. This standard reflects the complete and whole relationship between a person and the Creator, meaning an animal with any physical defect cannot be brought to the altar. Since the general rule against defective offerings is already established, the focus here is on the unique status of a firstborn animal. Because a firstborn possesses a natural holiness from the moment of its birth, one might assume this built-in sanctity allows it to be offered even if it is flawed [חזקוני]. However, the law clarifies that a defective firstborn still cannot be offered. Unlike other holy animals that require a redemption process to remove their sacred status, a flawed firstborn does not need to be redeemed. It simply remains in the priest's possession and may be eaten like regular, everyday meat [רלב"ג, רש"ר הירש].

A defect might develop during the animal's lifetime, well after it is born. To ensure there is no confusion, the law expands the rule to cover any severe flaw, including those an animal is born with directly from its mother's womb [תורה תמימה, מלבי"ם, חזקוני]. When detailing specific flaws, lameness is listed before blindness. This order highlights a key difference between humans and animals. For humans, sight is the most vital sense, so blindness is usually noted first. For animals, however, walking is the most prominent and essential function, making lameness the primary concern. In this context, lameness includes any significant limp, even if there is no actual broken bone, while blindness refers to a total loss of sight, even if the eye appears completely normal on the outside [העמק דבר].

The broad category of a severe defect is understood in two main ways. The primary approach among commentators is that the specific examples of lameness and blindness set the standard. Just as these are visible and incurable, any flaw that disqualifies an animal must be external and permanent, meaning internal or hidden issues do not disqualify the animal [רש"י, רש"ר הירש, צפנת פענח]. If a flaw appears temporary, one must wait to see if it becomes a permanent condition before making a final decision [רלב"ג]. Alternatively, other commentators understand this broad categorization as a way to include all defects mentioned anywhere else in the Torah [אבן עזרא, ביאור יש"ר]. This view expands the disqualification to include even minor but permanent physical flaws, such as a missing piece of ear cartilage as small as a fingernail clipping. It also covers any condition that fails to show proper honor to the altar, such as an animal that is old, sick, covered in boils or warts, or emitting a bad odor [תורה תמימה].